Wristwatch push-piece winding button control device

ABSTRACT

The device includes a support pipe driven into a bore of a watchcase, a push-piece crown consisting of a head and an extension mounted into the pipe in mobile manner, a part entraining rotation that is integral with the winding and setting stem of the watch, coupling elements causing the extension and the entraining part to move together in rotation as well as in translation in the direction of pulling, a first axial spring arranged between the crown&#39;s head and the entraining part, and a second axial spring arranged between the crown&#39;s head and the pipe. The first spring exerts a force that is high enough to overcome the resistance offered by stem during the change from the setting position to the winding position of the crown. The second spring exerts the principal restoring force bringing the crown back from its pushed position to its winding position.

The present invention refers to a push-piece crown control device for awatch, and more particularly to a push-piece crown control devicecomprising:

a support part that can be fixed at the watchcase or consists of thewatchcase itself, this support part having an opening,

a part entraining rotation that can be connected with the watch movementin order to control a first and second function of the watch such as awinding function and a setting function, respectively,

a crown comprising a head and an extension integral with the head thatis mounted into said opening so as to be mobile relative to the supportpart, said extension being able to cooperate with a control element of athird function of the watch, such as a function of start, stop, zeroreset, or fly-back of a chronograph, said control element being locatedinside the watchcase,

coupling organs for interlocking the entraining part and the crown'sextension so that they will rotate together and are integral intranslation in the direction of pulling, where when the watch is fittedwith the device, the crown may occupy a first stable axial position and,when pulled out, a second stable axial position, positions in which therotation of the entraining part imposed by the crown will control thefirst and second function, respectively, the crown in addition beingable to be pushed independently of the entraining part, from the firstaxial position to an axial position where the control element isactivated, and

first elastic means arranged between the entraining part and the crown'shead, said means exerting a force that is sufficient for overcoming theentraining part's resistance when passing from the second to the firstaxial position of the crown.

Such a device has been described in the document FR 923,922. It has thedisadvantage of subjecting the movement of the watch to a relativelyhigh stress exerted by the elastic means arranged between the crown'shead and the part entraining rotation, when the crown changes from thefirst axial position, here the winding position, to the position wherethe control element is activated, that is, to the pushed position. Uponrepeated use of the push-piece crown, this stress tends to wear outcertain parts of the movement, and may even provoke ruptures in themovement.

The present invention aims at obviating this drawback, and to this endprovides second elastic means arranged between the support part and thecrown's head, and like the first elastic means able to be compressedwhen the crown changes from the first axial position to the position ofactivation of the control element, in order to bring the crown back toits first axial position once the stress exerted by pushing the crownhas ceased.

Thus, in this invention the restoring force returning the crown from theposition of activation of the control element (pushed position) to thefirst axial position (neutral position or winding position) is sharedbetween the first and second elastic means. The first elastic means thusmay exert a weaker force than those of document FR 923,922. The movementis exposed to a stress of reduced intensity since during the change fromthe first axial position to the position of activation of the controlelement, the second elastic means rest on the support part of thedevice, rather than on the entraining part. Preferably, in order tominimise the intensity of this stress, the force exerted by the firstelastic means is just large enough to overcome the resistance offered bythe entraining part during the change from the second to the first axialposition, this force being lower than that exerted by the second elasticmeans which, thus, supply the principal restoring force bringing thecrown back from the position of activation of the control element to thefirst axial position.

Particular embodiments of the push-piece crown control device accordingto the invention are defined in the appended, dependent claims 3 to 11.

The present invention also provides a watch fitted with the push-piececrown control device as defined above.

Other characteristics and advantages of the invention will becomeapparent from the following detailed description provided whilereferring to the appended drawings in which:

FIG. 1 is a longitudinal sectional view of a push-piece crown controldevice according to the invention that is mounted on a watchcase, thepush-piece crown being represented in its winding position (neutralposition),

FIG. 2 is a longitudinal sectional view of a push-piece crown controldevice according to the invention that shows the push-piece crown in thesetting position (pulled-out position),

FIG. 3 is a longitudinal sectional view of the push-piece crown controldevice according to the invention that shows the push-piece crown in thepushed position,

FIG. 4 is an exploded perspective view of the device according to theinvention and of part of the associated watch, und

FIG. 5 is a perspective view of part of the watch associated with thedevice according to the invention that was taken at an angle differentfrom that of FIG. 4.

Referring to FIGS. 1 to 4, a push-piece crown control device accordingto the invention notably comprises a fixed support and guide pipe 1driven into a bore 2 going through the wall of the body (middle) 3 of awatchcase, and a push-piece crown 4 consisting of a crown's head 5 andof a tubular extension 6 that is integral with head 5. Extension 6consists of two parts, viz., a push-piece tube 7 having one of its twoends forced over a bush 8 of the crown's head 5, and an extension tube 9driven into the other end of the push-piece tube 7. Extension 6 ismounted so as to be mobile in the fixed pipe 1. Crown 4 thus can beturned and axially moved by the user in order to control differentfunctions in the watch, as will become apparent hereinafter.

A part 10 entraining rotation that appears in the shape of a piston orcylinder is mounted into the push-piece tube 7. This entraining part 10has a blind tapped hole 11 receiving the threaded end of a winding andsetting stem 12 of the watch, said stem 12 being connected with movementM of the watch and passing through bore 2 of the watchcase in theconventional manner, thus interlocking the entraining piece 10 with stem12.

Coupling means provided on the entraining part 10 and push-piece tube 7enable crown 4 to entrain rotation and translation in the direction ofpulling, of the entraining part 10, the direction of pulling being thedirection of increasing distance of crown 4 and part 10 from thewatchcase. In the illustrated example, these coupling means include asegment 13 with outer polygonal (for example hexagonal) cross section ofthe entraining part and a segment 14 with the corresponding innerpolygonal cross section of the push-piece tube 7 for entraining therotation, as well as an outer shoulder 15 of the entraining piece 10 anda corresponding inner shoulder 16 of the push-piece tube 7 forentraining translation in the direction of pulling.

The device according to the invention further includes a first and asecond helical spring 17, 18 arranged in axial direction between theunderside 19 of the crown's head 5 and the closed end 20 of theentraining part 10 inside the push-piece tube 7, and between theunderside 19 of the crown's head 5 and a shoulder 21 of the fixed pipe 1outside the push-piece tube 7. The first spring 17 is freely mountedinto the cylindrical seat defined by bush 8 of the crown's head 5. Thesecond spring 18 is freely mounted into an annular seat defined by theoutside 22 of the push-piece tube 7, by an end segment 23 of the insideof fixed pipe 1, and by shoulder 21 of the fixed pipe 1.

Two annular gaskets 24, preferably thoric, which are held compressedbetween the inner side face of the crown's head 5 and the outside offixed pipe 1 secure water resistance of the device in all positions ofcrown 4.

For interlocking of the entraining part 10 with the winding and settingstem 12, and for interlocking of crown 4 with the entraining part 10,crown 4 and entraining part 10 can assume a neutral axial position orwinding position as illustrated in FIG. 1, as well as a pulled axialposition or setting position as illustrated in FIG. 2. These two axialpositions are indexed in the classical way by movement M of the watch.In the neutral position, springs 17 and 18 are both relaxed. The changefrom the neutral position to the pulled position is brought about by theuser pulling crown 4, said crown 4 entraining the entraining part 10 byvirtue of the cooperation of shoulders 15 and 16. If subsequently theuser pushes crown 4 in order to bring it back to the neutral position,the entraining part 10 and the winding and setting stem 12 will bepushed by the first spring 17 exerting a force that is high enough toovercome the resistance offered by these elements 10 and 12, aresistance arising within the winding and setting mechanism inside themovement M, or more precisely from the group of setting lever jumper andlever spring (not represented) of movement M.

From its neutral position, crown 4 in addition can be axially moved inthe direction of the watchcase until reaching a position called“pushed”, independently of the entraining part 10 and winding andsetting stem 12 which then remain immobile (FIG. 3). In this pushedposition, crown 4 or more precisely the extension tube 9 will activate acontrol element 25 inside the watchcase. This control element 25 may forinstance be a start lever, a stop lever, a zero resetting lever, or afly-back lever of a chronograph, a time-zone change lever or any other,analogous element.

During the change from the neutral position to the pushed position ofcrown 4, springs 17 and 18 become compressed. As soon as the pushingforce exerted by the user on crown 4 ceases, springs 17 and 18 relax andbring crown 4 back to its neutral position (FIG. 1). It will be notedthat the restoring force bringing crown 4 back to its neutral positionwill thus be shared between springs 17 and 18, and that in the pushedposition of crown 4 the parts 10 and 12, and thus the movement M, arenot subject to stress exerted by the second spring 18, inasmuch as thisspring rests against the fixed pipe 1.

It will further be observed that by having a first spring 17 exerting aforce high enough to overcome the resistance offered by movement Mduring the change from the pulled position to the neutral position, oneescapes the obligation of completely pushing back crown 4 in order toreturn the entraining part 10 and the stem 12 from their pulled positionto their neutral position, an action which would cause an undesiredactivation of the push-piece function of crown 4.

Preferably, the first spring 17 exerts a force that is just high enoughto overcome the resistance offered by movement M during the change fromthe pulled position to the neutral position of crown 4, while the secondspring 18 exerts a force that is higher than that of the first spring17, and thus constitutes the principal restoring force bringing crown 4back to its neutral position. In this way the stress to which movement Mis exposed when crown 4 is pushed from its neutral position isminimised.

According to another characteristic of the invention, a first and asecond formation 26, 27 are provided, one at the crown's head 5 and onein the terminal segment of largest diameter 28 of bore 2 of thewatchcase into which the crown's head 5 is engaged when crown 4 is inits pushed position. These formations 26, 27 admit the change of crown 4from its neutral position to its pushed position, only when they arealigned, thus avoiding any untimely activation of the control element25. In the example illustrated, these formations are a groove 26parallel to the axis of crown 4 on the periphery of the crown's head 5,and a projection 27 provided at the flank of the segment 28 of largestdiameter of the bore in the watchcase. Reference marks may be applied tothe crown's head 5 and watchcase in order to indicate the positions ofthese formations 26, 27 to the user.

The invention as described above offers several advantages over thepush-piece crown control device according to the document FR 923,922,and particularly:

the fact that had already been pointed out, that movement M is subjectonly to the stress exerted by the first spring 17 (and not to thatexerted by the second spring 18) when crown 4 is pushed from its neutralposition; this first spring 17 can be less strong than the spring usedin the device according to the document FR 923,922, inasmuch as it isnot its function to exert the principal restoring force bringing crown 4back from its pushed position to its neutral position, whence thepossibility for movement M to be subject to a stress of reducedintensity while crown 4 is pushed;

the device is made completely resistant against water and dust, bymerely two gaskets (the toric gaskets 24) that are very easy to replace(a single one of these gaskets may suffice, moreover); in addition, thisresistance is obtained in all axial positions of crown 4;

the two-part design of extension 6 of crown 4 (the push-piece tube 7 andthe extension tube 9) yields an easy, cheaper adaptation of the lengthof this extension 6 to the pathlength of the control element 25 ofmovement M, by appropriate selection of the length of extension tube 9;

all untimely activation of control element 25 is inhibited by theformations 26, 27 that are provided.

The invention has been described above, merely in terms of an example.It is obvious that modifications could be made without leaving the scopeof the invention claimed. Fixed pipe 1 could for instance be left out.Extension 6 of crown 4 would then be mounted directly into bore 2 of thewatchcase, and spring 18 would be arranged between the crown's head 5und the shoulder defined by the segment 28 of largest diameter of bore2. Another modification could be that of realising crown 4 (head 5 andextension 6) as a single part. The group of entraining part 10 and stem12 could also be realised as a single part. Locking means such as abayonet system could equally well be provided in order to lock crown 4in its pushed position, in such a way that it can be liberated, if sucha function is made possible or necessary by the characteristics of themovement. In this last realisation, formations 26 and 27 would be leftout or adapted to the locking means.

1. Push-piece crown control device for a watch, comprising: a supportpart (1) that can be attached to the watchcase (3) or may consist of thewatchcase (3) itself, this support part (1) having an opening, a part(10) entraining rotation that can be connected with the movement (M) ofthe watch in order to control a first and a second function of thewatch, a crown (4) comprising a head (5) and an extension (6) integralwith the head (5) and mounted into said opening so as to be mobilerelative to the support part (1), said extension (6) being able tocooperate with a control element (25) for a third function of the watchthat is located inside the watch-case (3), coupling means (13, 14, 15,16) acting so as to make the entraining part (10) and the extension (6)of crown (4) move together in rotation as well as in translation in thedirection of pulling, crown (4) being able when the watch is fitted withthe device, to occupy a first stable axial position and a second stableaxial position where it is pulled, positions in which the rotation ofthe entraining part (10) imparted by crown (4) controls the first andsecond function, respectively, the crown (4) being able in addition tobe pushed independently of the entraining part (10) from its first axialposition up to an axial position of activation of the control element(25), and first elastic means (17) arranged between the entraining part(10) and the crown's head (5) and exerting a force that suffices toovercome the resistance offered by the entraining part (10) during thechange from the second to the first axial position of the crown (4),characterised in that it comprises in addition: second elastic means(18) arranged between the support part (1) and the crown's head (5), andable to be compressed during the change of crown (4) from its firstaxial position to the position of activation of the control element(25), in order to return the crown (4) to its first axial position oncethe stress exerted by pushing the crown (4) has ceased.
 2. Deviceaccording to claim 1, characterised in that the force exerted by thesecond elastic means (18) is larger than that exerted by the firstelastic means (17).
 3. Device according to claim 1, characterised inthat the first and second elastic means consist of a first (17) andsecond (18) axial spring, respectively.
 4. Device according to claim 1,characterised in that the support part (1) is a pipe intended to befixed at the watchcase (3).
 5. Device according to claim 4,characterised in that additionally it comprises at least one annulargasket (24) compressed between an inner side face of the crown's head(5) and the outside of the support pipe (1).
 6. Device according toclaim 1, characterised in that the extension (6) of the crown (4) istubular and axial, and in that the entraining part (10) is mountedinside this extension.
 7. Device according to claim 6, characterised inthat the extension (6) comprises a first tube (7) integral with thecrown's head (5) and a second tube (9) connected with the first tube(7).
 8. Device according to claim 1, characterised in that the couplingmeans comprise a segment of outer polygonal cross section (13) of theentraining part (10) and a segment of corresponding inner polygonalcross section (14) of the extension (6) of crown (4) for entrainingrotation of the entraining part (10), as well as an outer shoulder (15)of the entraining part (10) and a corresponding inner shoulder (16) ofthe extension (6) of crown (4) for entraining translation in thedirection of pulling.
 9. Device according to claim 1, characterised inthat the entraining part (10) is a cylinder open at one end in order toreceive an end of an entraining stem (12) of the watch.
 10. Deviceaccording to claim 1, characterised in that the first and secondfunction are a winding function and a setting function, respectively.11. Device according to claim 1, characterised in that the crown's head(5) comprises a formation (26) intended to cooperate with acorresponding formation (27) provided in an opening (28) of thewatchcase (3) in order to admit a change of the crown (4) from the firstaxial position to the position of activation of the control element(25), only when said formations (26, 27) are aligned.
 12. Watch providedwith a control device according to claim
 1. 13. Device according toclaim 2, characterised in that the first and second elastic meansconsist of a first (17) and second (18) axial spring, respectively.